Method: Mustermann::Expander#cast

Defined in:
lib/mustermann/expander.rb

#cast {|key, value| ... } ⇒ Mustermann::Expander #cast(*type_matchers) {|key, value| ... } ⇒ Mustermann::Expander #cast(*cast_objects) ⇒ Mustermann::Expander

Register a block as simple hash transformation that runs before expanding the pattern.

Overloads:

  • #cast {|key, value| ... } ⇒ Mustermann::Expander

    Register a block as simple hash transformation that runs before expanding the pattern for all entries.

    Examples:

    casting everything that implements to_param to param

    expander.cast { |o| o.to_param if o.respond_to? :to_param }

    Yields:

    • every key/value pair

    Yield Parameters:

    • key (Symbol) —

      omitted if block takes less than 2

    • value (Object) —

      omitted if block takes no arguments

    Yield Returns:

    • (Hash{Symbol: Object}) —

      will replace key/value pair with returned hash

    • (nil, false) —

      will keep key/value pair in hash

    • (Object) —

      will replace value with returned object

  • #cast(*type_matchers) {|key, value| ... } ⇒ Mustermann::Expander

    Register a block as simple hash transformation that runs before expanding the pattern for certain entries.

    Examples:

    convert user to user_id

    expander = Mustermann::Expander.new('/users/:user_id')
expand.cast(:user) { |user| { user_id: user.id } }

expand.expand(user: User.current) # => "/users/42"

    convert user, page, image to user_id, page_id, image_id

    expander = Mustermann::Expander.new('/users/:user_id', '/pages/:page_id', '/:image_id.jpg')
expand.cast(:user, :page, :image) { |key, value| { "#{key}_id".to_sym => value.id } }

expand.expand(user: User.current) # => "/users/42"

    casting to multiple key/value pairs

    expander = Mustermann::Expander.new('/users/:user_id/:image_id.:format')
expander.cast(:image) { |i| { user_id: i.owner.id, image_id: i.id, format: i.format } }

expander.expander(image: User.current.avatar) # => "/users/42/avatar.jpg"

    casting all ActiveRecord objects to param

    expander.cast(ActiveRecord::Base, &:to_param)

    Parameters:

    • type_matchers (Array<Symbol, Regexp, #===>) —

      To identify key/value pairs to match against. Regexps and Symbols match against key, everything else matches against value.

    Yields:

    • every key/value pair

    Yield Parameters:

    • key (Symbol) —

      omitted if block takes less than 2

    • value (Object) —

      omitted if block takes no arguments

    Yield Returns:

    • (Hash{Symbol: Object}) —

      will replace key/value pair with returned hash

    • (nil, false) —

      will keep key/value pair in hash

    • (Object) —

      will replace value with returned object

  • #cast(*cast_objects) ⇒ Mustermann::Expander

    Parameters:

    • cast_objects (Array<#cast>) —

      Before expanding, will call #cast on these objects for each key/value pair. Return value will be treated same as block return values described above.

Returns:



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# File 'lib/mustermann/expander.rb', line 115

def cast(*types, &block)
  caster.register(*types, &block)
  self
end